def test_nnf_LPL_page_321_antecedent():
tw = tarskiworld.create_small_world()
x = tw.variable('x', tw.Object)
y = tw.variable('y', tw.Object)
s = forall(x, neg(land(tw.Cube(x), exists(y, land(tw.Tet(x), tw.LeftOf(x, y))))))
result = NNFTransformation.rewrite(s)
gamma = forall(x, lor(neg(tw.Cube(x)), forall(y, lor(neg(tw.Tet(x)), neg(tw.LeftOf(x, y))))))
assert str(result.nnf) == str(gamma)
def test_nnf_quantifier_flips():
bw = tarski.benchmarks.blocksworld.generate_fstrips_bw_language()
block = bw.get_sort('block')
loc = bw.get_function('loc')
b1, b2, b3, b4 = [bw.get_constant('b{}'.format(k)) for k in range(1, 5)]
x = bw.variable('x', block)
phi = neg(exists(x, loc(x) == loc(b2)))
result = NNFTransformation.rewrite(phi)
gamma = forall(x, neg(loc(x) == loc(b2)))
assert str(result.nnf) == str(gamma)
def test_nnf_double_negation():
bw = blocksworld.generate_small_fstrips_bw_language()
block = bw.get_sort('block')
place = bw.get_sort('place')
loc = bw.get_function('loc')
clear = bw.get_predicate('clear')
b1, b2, b3, b4 = [bw.get_constant('b{}'.format(k)) for k in range(1, 5)]
table = bw.get_constant('table')
phi = neg(neg(loc(b1) == loc(b2)))
result = NNFTransformation.rewrite(phi)
gamma = loc(b1) == loc(b2)
assert str(result.nnf) == str(gamma)
def test_prenex_lpl_page_321():
tw = tarskiworld.create_small_world()
x = tw.variable('x', tw.Object)
y = tw.variable('y', tw.Object)
s1 = exists(y, land(tw.Dodec(y), tw.BackOf(x, y)))
s2 = land(tw.Cube(x), exists(y, land(tw.Tet(y), tw.LeftOf(x, y))))
phi = forall(x, implies(s2, s1))
result = PrenexTransformation.rewrite(tw, phi)
yp = tw.variable("y'", tw.Object)
gamma = NNFTransformation.rewrite(exists(yp, forall(
x, y, implies(land(tw.Cube(x), land(tw.Tet(y), tw.LeftOf(x, y))), land(tw.Dodec(yp), tw.BackOf(x, yp)))))).nnf
assert str(result.prenex) == str(gamma)
def test_nnf_conjunction():
bw = tarski.benchmarks.blocksworld.generate_fstrips_bw_language()
_ = bw.get_sort('block')
_ = bw.get_sort('place')
loc = bw.get_function('loc')
_ = bw.get_predicate('clear')
b1, b2, b3, b4 = [bw.get_constant('b{}'.format(k)) for k in range(1, 5)]
_ = bw.get_constant('table')
phi = neg(land(loc(b1) != loc(b2), loc(b3) != loc(b4)))
result = NNFTransformation.rewrite(phi)
gamma = lor(neg(loc(b1) != loc(b2)), neg(loc(b3) != loc(b4)))
assert str(result.nnf) == str(gamma)
def test_nnf_quantifier_flips():
bw = blocksworld.generate_small_fstrips_bw_language()
block = bw.get_sort('block')
place = bw.get_sort('place')
loc = bw.get_function('loc')
clear = bw.get_predicate('clear')
b1, b2, b3, b4 = [bw.get_constant('b{}'.format(k)) for k in range(1, 5)]
table = bw.get_constant('table')
x = bw.variable('x', block)
phi = neg(exists(x, loc(x) == loc(b2)))
result = NNFTransformation.rewrite(phi)
gamma = forall(x, neg(loc(x) == loc(b2)))
assert str(result.nnf) == str(gamma)